Blasting method and apparatus



Dee. 14,1926. 1,610,274

D. FERRELL ET AL BLASTING METHOD AND AFPARAT'US QQ Original Filed Feb.1l, 1925 N Q N gw Patented Dec.l 14, 1926.

UNITED STATES PATENT OFFICE.

DENT FEBBELL, .ARTHUR W. HELMHOLTZ, AND JOHN H. CBAWFOBI), F HARRIS-.'BUBG, ILLINOIS, ASSIGNORS T0 SAFETY PRESSURE MINING & EQUIPMENT COMPANY, 0F HABRISBURG, ILLINOIS, A CORPORATION OIE' ILLINOIS.

BLASTINGj METHOD .ND APPARATUS.

Application'led February 11, 1925, Serial No. 8,328. Renewed lJecember19, 1925.

This invention relates toa new and improved blasting method and to anapparatus adapted for carrying out the method.

In mine operation by blasting with the use of explosives as now commonlycarried out, it is necessary to clear the mine of the operatingpersonnel before setting oi the blast. This is due to the danger topersonnel from fumes and gases evolved by the blast and also Ato thedangenof ignition of mine gases or powdered coal by the highly heatedblast gases. These requirements prevent more than one blast in each heador room for each shift and consequently, slowing up production. Y

According to our present invention, we blast by means of apparatusgiving o no dangerous gases and without the development of dangeroustemperatures. The present invention is in the nature of a modificationand improvement of our prior application, Serial' No. 710,724, liled May3,.

l924.-l In that application, we have disclosed the rupture of a closedcontainer by the gasification of a non-gaseous material by the means ofheat.

According to the present invention, we provide heat producing meanslocated within the container and adapted to not only produce heat but toviolently agitate the carbon dioxide and thus facilitate the trans- :Eerof the heat.

It is an object of the present invention to provide a new and improvedmeans and method forv blasting without the generation of dangerous heator gases.

llt is a further object to provide a means and method of this characteradapted for use by simple apparatus and which may be utilized withoutdanger to mine personnel.

It is also an object to provide a means and method whereby the blastingforce is supplied by the sudden gasification and liberation of a gasheld in liquid form in a closed container.

It is an additional object to provide means wherein the heat necessaryfor gasiication is supplied internally of the container together withViolent agitation of the material. a v

Other and further objects will appear as the description proceeds.

lVe have illustrated a preferred embodimentpf our lnvention in theaccompanying drawings in Which- Figure 1 is a longitudinal-section toone form of cartridge;

Figure 2 is a view of the cartridge as seen from the right of Figure l,and- Figure 3v is a fragmentary view similar to Figure l but showing amodified form of construction.

The cartridge comprises the cylindrical outer casing l1, into the rightendvowhich 1s secured the ring 12. This ring has been shown as threadedinto the casing l1, but it may be brazed or welded or otherwisepermanently secured in place. The face 13 of the ring isrounded oli' tominimize the reslstance offered to the vpassage O gases outwardlythrough the ring. The outer axlal face of the ring is recessed toreceive the packing 14. The outer ring 16 which is threaded into thecasing 11, as best shown in Figure 2, is provided with the hexagonalopening 17 by means of which it may be Vsecured tightly in position bythe use of a Wrench.

The disk 15 is held against the packing 14 by the ring 16 and isprovided with the circular groove 18, which may be any desired depth.The thickness of the material left at the base of the groove 18 willdetermine the force required to rupture the disk on the line of thegroove and consequently blow out the central part of the dlsk. The innerface ofthe disk is provided With a stud 19 and adapted to support thetubular member 20.

The ring 21 is screwed into the opposite end of the casing 11. This ringcarries the insulating packing member 22 and supports the plug 23, whichextends through the ring. The outer end of the plug 23 is threaded andreceives the ring 24 which bears against the outer face of the packing22 and retains the plug in place. The plug 23 is provided with the axialpassage 25 communicating through passages 26 with the interior of thecasing.

The needle Valve 27 is threaded into the outer end of the plug andreceives the needle valve member 28. The housing is provided with thethreaded opening 29 adapted to beconnected to a source of Huid supply.The valve is protected by a housing member 30 secured to the outerportion of plug 23 by means of disk 31.

The electrical conductor 32 is secured to the casing 11 and theconductor 33 is secured to the ring 24..` It will be noted that the plugand the associated rings and. valve housingare insulated from thehousing.

The member 20 is formed of conducting material and consequently, currentwill pass through conductor 33 to the plug and thence through member 20to disk 19 and to the housin 11. From the housing 11 it flows throngconductor 32 back to *the source of current supply.

In ythe form of construction shown in Figure 3 all of the elements arethe same as described with the exception of the member 20, For themember 20 is substituted a tubular member 34 formed of non-conductingfluid-proof material. Enclosed within this member is the electricalconductor 35, the ends of which make electrical contact with the nipple36 on the plug 23 and also with the stud 19 on the disk 15. The tubularmember 34 is filled varound the conductor 35 with combustible material37 adapted for combustion attended by large heat liberation. Thismaterial may be ordinary black powder. l

' In the use of either form of construction shown, after the parts havebeen put in place, a source of fluid under pressure is connected to theopening 29A in the needle valve. The valve is opened and liuid isintroduced into the casing up to the desired pressure. The valve is thenclosed and the source of supply disconnected. The housing member 30 isthen screwed in place to protect the valve against accidental injury oropening.

It will be understood that the disk 15 fitted into the cartridge will beadapted to rupture at the desired blasting pressure. The liquidintroduced into the cartridge will be brought to a pressure Suiiicientlyless than the rupturing pressure of the disk, so as to render thecartridge entirely safe for handling. The conductors 32 and 33 areconnected to a suitable source of electric current, the switchcontrolling which, however, is held open.' The cartridge is thenintroduced into the drill hole and is tamped in place in the same manneras a charge of dynamite.

In the form of construction shown in Figure 1, it will be necessary tosupply a relatively large amount of electricity. It is desired to supplysuilicient current so as to cause the member 20 to blow out, or to besubstantially instantaneously fused and atomized by the current. Thisvaporized or asified metal passing into the liquid in all irections veryquickly heats the whole body of liquid and raises it to such temperatureas to raise its rassure above that re uired for rupturing t e disk l5,The disk lows out and releases the imprisoned liquid which has beengasiied by the heat and which has a blasting effect in the drill hole.

In the form of construction shown in Figure 3, only a small amount ofcurrent is necessary. The conductor 35 need merely be heated to such atemperature as to cause the detonation of the black powder or otherexplosive'37. The explosion of this powder raises the temperature of thesurrounding liquid suiciently to gasify it and cause the rupture of thedisk l5 and the consequent desired blasting action.

The liquid which is preferably used is carbon dioxide. This liquid whengasiied will form so smalla portion of the air in the mine as to have noharmful eiects. The sudden expansion of the gas will have arefrigerating action and consequently, there will be no dangerous heatevolved from the blasting action. With thel form of constructioninvolving the use of black powder, it will be possible lto use such asmall portion of powder vas to have no appreciable defect upon the air.The heat from the powder will be dissipated through a large volume ofcarbon'dioxide gas evolved upon the blasting rupture of the container.Consequently, either method of gasifying the carbon dioxide may be usedwithout danger to persons in the mine. It will simply be necessary forthe personnel to move far enough away from the working face to be out ofdanger from iying :tiragments.

After the blast, the cylinders may be recovered and the only partsdestroyed will be the member 20, or its equivalent in the forni ofFigure 3, and the disk 15. The outer ring 16 may be removed and a newmember 2O and disk l5 inserted. The casing may then be filled withliquides before and used again. The cost of operation is therefore keptvery low since the parts to be replaced are relatively inexpensive andthe carbon dioxide may be cheaply secured. While We have mentionedcarbon dioxide as a suitable substance to. be used, it will beunderstood that we .may employ other material in the non-gaseous state,such as air, nitrogen, etc.

While We have illustrated certain preferred forms by way of example, itis to be understood that `we contemplate such changes and modificationsas come within the spirit and scope of the appended claims.

We claim:

1. The method of blasting which comprises coniining in a closedcontainer a compressible fluid not a liquid under atmospherictemperatures and pressures, and applying to said Huid a gasitying heatby means of the vaporization of an electrical llo igeiaa'm conductor inthe container, the gasification producing a pressure suilicient torupture a Wall of the container.

2. The method of blastin which comprises confining carbon dioxi e in thenon-- gaseous state in a closed container, and applying to said carbondioxide a gasifying heat by means of the vaporization of an electricalconductor inthe container, the gasification producing a pressuresuiiicient to rupture a Wall of the container.

3. 'l`he method of blasting which coniprises coniningin a closedcontainer a compressible fluid not a liquid under atmospherictemperatures and pressures, and applying to said fluid a gasifying heatby means of the vaporization of an electrical conductor and thedetonation of. an explosive in the container, the gasification producinga pressure sufficient to rupture a wall of the container.` f

4. The method of blasting which comprises coniining .carbon dioxide in aclosed container, and applying to said carbon dioxide a gasifying heatby means of the fu; sion of an electrical conductor and the combustionof material accompaniedby large heat liberation in the container, thegasiiication producing a pressure sufficient to rupture a wall of thecontainer.

5. 'lhe blasting cartridge comprising a casing, means whereby a Huidunder pressure may be introduced into the casing, a fusible electricalconductor n the casing and electrical connections for the conductorextending exteriorly of the casing.

6. A blasting cartridge comprising a casing, a removable and replaceableWall section in the casing, said section being rupturable at lesspressure than the remainder i.

of the casing, means whereby ra. Huid under pressure may be introducedinto the casing, a fusible electrical conductor in tlie casing, andelectrical connections for the conductor extendino exteriorly of thecasing.

7. A blasting cartridgeJ comprising a casing, means whereby a li-uidunder pressure may be introduced into the casing7 a vaporizableelectrical conductor extending length- Wise of the casing and having oneend secured to the casing and the other end secured to a plug insulatedfrom the casing and extending through a wall thereof.

8. A blasting cartridge comprising a casing, means whereby a. Huid underpressure may be introduced into the casing, a fusible .electricalconductor in the casing, a body of material located adjacent the fusibleconductor, said material being ignitable by neat and adapted forcombustion attended by large heat liberation, and electrical connectionsfor the conductor extending exteriorly of the casing..

9. A blasting cartridge comprising a casing, means Whei'eby a iluidunder pressure may be introduced into the casing, an innercasingextending longitudinally or' the casing, a material in said inner"casing, said material being ignitible by heat and adapted forcombustion attended by large heat liberation, a. fusible electricalconductor extenuinginto the inner casing and having one end secured totn'e outer casing and the other end secured to a plug insulated from theouter casing and extending through a wail thereof. y

Signed at Harrisburg,"lllinois, this 7th day or' February, 1925. y

DENT FERRELL. A. W. HELMHOLTZ.- JOHN CRAWFORD.

